1. Field
One embodiment of the invention relates to a technology to supply power to a device, and more particularly, to an information processor that supplies power to a device via a bus and a power supply method.
2. Description of the Related Art
Recent information processors including personal computers (PCs) are provided with a bus interface, such as a universal serial bus (USB) and an institute of electrical and electronic engineers (IEEE) 1394 bus, to connect to various types of devices. Such an information processor is capable of supplying power to a device through the bus interface. For example, Japanese Patent Application Publication (KOKAI) No. 2006-53748 discloses a conventional technology to supply power from an information processor to a device through a bus interface. According to the conventional technology, even if the information processor is OFF or in power saving mode, when the device is connected to the bus interface, it starts power supply to the device. The mode in which the information processor supplies power to a device (hereinafter, “power supply mode”) varies depending on the device. If a wrong power supply mode is selected to supply power to a device, power may not be supplied properly to the device.
If required to select a power supply mode suitable for a device, the user needs the knowledge as well as the time to do so. This is inconvenient to the user.